Congenital aortic sinus aneurysm is a rare congenital cardiac anomaly. This condition is often detected in adulthood and is more common in males than in females.
Pathological Anatomy
The lesion primarily occurs in the aortic sinus. With age, the aneurysm gradually enlarges and protrudes into the cardiac chambers. When the aneurysm reaches a certain size, the wall may thin and rupture. The aneurysm can rupture into the right atrium, right ventricle, pulmonary artery, left ventricle, or pericardial cavity. Some patients may also have associated ventricular septal defects.
Pathophysiology
The pathophysiological changes vary depending on the location of the aneurysm and the chamber into which it ruptures. For example, if the aneurysm ruptures into the pericardial cavity, it can cause acute cardiac tamponade and rapid death. Clinically, rupture of a right coronary sinus aneurysm into the right ventricle is more common and presents with typical pathophysiological features resembling acute left-to-right shunting at the ventricular level.
Clinical Manifestations
When the aneurysm ruptures, patients may experience acute symptoms of heart failure, including palpitations, chest pain, dyspnea, and cough. Over time, signs of right heart failure gradually develop. A characteristic clinical finding is a loud, continuous machinery murmur, accompanied by a thrill, heard at the 3rd or 4th intercostal space along the left sternal border.
Auxiliary Examinations
Electrocardiography (ECG)
ECG may show evidence of left or right ventricular enlargement.
Chest X-ray
After rupture, findings may include pulmonary congestion and enlargement of both the left and right ventricles.
Echocardiography
Before rupture, an enlarged aortic sinus with a saccular protrusion can be visualized. After rupture, a tear in the aneurysm wall can be detected, and Doppler imaging can reveal blood flow shunting through the rupture.
Cardiac Catheterization
It provides an accurate assessment of the rupture location and the volume of the shunt.
Diagnosis and Differential Diagnosis
With the advancement and widespread use of imaging techniques, the detection of unruptured aortic sinus aneurysms has increased. For patients with no prior diagnosis of an aortic sinus aneurysm, acute symptoms and signs should prompt differentiation from conditions such as acute myocardial infarction, patent ductus arteriosus, and ventricular septal defect with aortic regurgitation.
Treatment
Unruptured aneurysms are typically managed conservatively with regular follow-up.
In cases of ruptured aneurysms, prompt treatment is essential.
Treatment options include interventional therapy and surgical therapy.
Prognosis
The prognosis is poor once the aneurysm ruptures; without surgical treatment, most patients die within weeks or months due to heart failure.